<!DOCTYPE html>
<html>
     <head>
<meta charset="utf-8"/>
<title>变量</title>
     </head>
    <body>
          <script type="text/javascript">
                /* var a = '456';
                b = '666';
                console.log(a);
                console.log(b); */


                var a = '456';
                var b = '666';
                var c;
                console.log(a);
                console.log(b);
                console.log(c);
                c=234;
               console.log(d);
                var d = 35;
               









          </script>
     </body>
</html>